docs: def wait(self, timeout=None):
          """Wait for a change in the journal.
  
          `timeout` is the maximum time in seconds to wait, or None which
          means to wait forever.
  
          Returns one of NOP (no change), APPEND (new entries have been added to
          the end of the journal), or INVALIDATE (journal files have been added or
          removed).
          """
          us = -1 if timeout is None else int(timeout * 1000000)
          return super(Reader, self).wait(us)